Catalytic Weak Efficiency
 

Hey guys need some help. bought an 06 evo mr about a month and a half ago without any cats so i had to put a cat on it so i could register it and get a vin inspection done had no CEL's for about 2 weeks now i just popped one saying Catalytic Weak Efficiency. anyone have experience with this? if so please give me some suggestions so this CEL wont pop. thanks a bunch:thumbup:

is it a race cat? they throw cat codes a lot too. Any tuner can get rid of the code in about 5 minutes.

Don't need a tuner to get rid of the code if it involves the rear O2. Need a tactrix cable, windows machine and mosey over to the stock ECU forum.

If its a stock cat, its bad or the sensor is bad. If its a high-flow cat as the previous poster mentioned, its normal.

If you dont want to modify the ECU, you can get the Vibrant O2 sensor spacer kit to prevent the code. It moves the o2 sensor out of the exhaust flow a bit to make it read lower, thus prevent the code from coming up.

Nah not a stock cat its an aftermarket one and i did move the rear o2 sensor out a bit